CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Class A Stock	Class B Stock	Common Stock Class A Stock	Common Stock Class B Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)
Balance (in shares) at Dec. 31, 2017				252,000,000	300,000
Balance at Dec. 31, 2017	$ 392			$ 3	$ 0	$ (3)	$ 3,526	$ (3,134)
Increase (Decrease) in Stockholders' Equity
Share-based compensation (in shares)				4,000,000	0
Share-based compensation	12			$ 0		2	10
Net loss	(1,003)							(1,003)
Balance (in shares) at Dec. 31, 2018		256,000,000	1,000,000	256,000,000	300,000
Balance at Dec. 31, 2018	(599)			$ 3	$ 0	(1)	3,536	(4,137)
Increase (Decrease) in Stockholders' Equity
Share-based compensation (in shares)				(1,000,000)
Share-based compensation	9					0	9
Net loss	(943)							(943)
Balance (in shares) at Dec. 31, 2019		256,000,000	1,000,000	255,000,000	300,000
Balance at Dec. 31, 2019	$ (1,533)			$ 3	$ 0	$ (1)	$ 3,545	$ (5,080)